1. Field of the Invention
The invention relates generally to optical recording media such as for example, digital video disks (DVDs), compact disks (CDs) and compact disk read only memories (CD-ROMs). More particularly, the present invention relates to optical recording media having both a mainly read-only part containing information recorded in a manufacturing process and a read/write part in which information can be written, erased, changed and read subsequent to the manufacturing process.
2. Description of the Related Art
Current read-only optical technology enables large amounts of information to be permanently stored on a relatively small optical medium. However, it has a problem that the original information cannot be changed and additional information cannot easily be written to the disk after original information has been recorded in a manufacturing process. Furthermore, the original information is usually pre-recorded in a standard format which cannot be changed. Read/write optical technology is developing but is not widely in use.
A conventional read-only CD typically contains a plurality of different songs recorded at once on a large number of CDs in a mass manufacturing process. Programmable CD players are available which can be programmed by a user to read and play only selected ones of the songs on a CD and to play the selected songs in a certain order according to a user's personal tastes. The program is stored in a memory within the CD player. However, if the CD is played in another CD player, then the user has to program that other CD player as well. And if a CD player cannot distinguish between different CDs and the user wishes to have a customized program for each one of the different CDs, they then have to reprogram the CD player each time a different CD is put into the player.
Some CD players may be configured so that they can detect and distinguish between CDs on the basis of information, such as serial number or code number, recorded on the CDs during the manufacturing process, store customized programs keyed to respective corresponding one of the CDs, and execute the customized program corresponding to an identified CD. Even so, because the customized program is stored in a memory of the CD player, if the CD player becomes inoperable, loses power or suffers a power surge, or if the memory fails for any reason, then the program is irretrievably lost and the user again has to reprogram the CD player. Such reprogramming is especially time consuming if the CD player is a jukebox type CD player containing, for example, a number of different programs for a large number of different CDs.
Of course, machines such as DVD players or personal computers may also be configured to accept a number of different types of customizations keyed to corresponding CDs besides playback programs. For example, the machines may be customized to display the title, artist or other information related to a song to be played or other information to be read from the recording medium. Since conventional read-only optical disks contain information recorded in accordance with a highly structured standard format, it is not possible to add such supplementary information to the disk. Therefore, even though optical recorders are available which can write onto optical recording mediums, they cannot be used to record additional information onto media already having pre-recorded information recorded according to a highly structured standard format in a manufacturing process.